The present invention relates to a developing device in the field of an electrophotographic full color image forming apparatus and a method for using such a developing device.
Three developing units in which developers (each containing toner and carrier) of three primary colors are filled respectively are mounted on the electrophotographic full color image forming apparatus. Alternately, such an image forming apparatus may be further provided with another developing unit in which a black developer is filled. These developing units are arranged such that they face one or a plurality of photosensitive drums in an opposing manner. An image forming process is carried out by visualizing or developing electrostatic latent images with plural developers which are applied in sequence.
Because of the high fluidity of the developer containing toner and carrier, however, during the transportation of the electrophotographic full color image forming apparatus, due to an impact or a vibration which the apparatus receives, the developer filled in the developing unit may overflow from an opening through which a developing roller is exposed outside.
In such a case, there arises a problem that the overflown developer may hamper favorable prints after installing the electrophotographic full color image forming apparatus.
Such a tendency is becoming more apparent these days since handling of these apparatuses during transportation has been facilitated due to downsizing of apparatuses which enables transportation of the apparatuses even when their posture is up side down.